BEIJING, Mar. 11 -- At the beginning of this month, China established its first space trash observation center, Space Target and Debris Observation and Research Center of the Chinese Academy of Sciences (CAS), at the Purple Mountain Observatory (PMO) of CAS's Nanjing branch. The center would set up an early-warning system for China's aerospace field.

Space debris, commonly known as space trash, refer to the debris left by humans in space, ranging from deserted satellites and metal components of various spacecrafts to residues and powder produced by ignition of solid fuel engines.

It is estimated that currently there are over 110,000 pieces of untracked space debris with diameters more than 1 cm in space and over 40 million pieces with diameters of more than 1 mm. The debris weighs about 3000 tons and is increasing at a rate of 2% to 5% every year.

Scientists at PMO pointed out that at this speed, nothing would be able to enter the space orbit by 2300. The observation and research of space debris aims to protect manned spaceship and expensive large satellites.